Calcium Scoring Scan Research Articles

Detection of monosodium urate depositions and atherosclerotic plaques in the cardiovascular system by dual-energy computed tomography

AimThe study aimed to explore the relationship between urate deposition and surrounding atherosclerotic plaques, and to confirm the contribution of urate deposition to the development of coronary atherosclerosis. Methods and resultsThe present study employed Dual-energy CT (DECT) material separation technology through calcium score scan to access the presence of MSU crystal deposition in coronary atherosclerotic plaques in patients with clinically suspected coronary heart diseases undergoing DECT. DECT showed that among 872 patients, 441 had plaques in coronary arteries; the incidence of plaque was 50.6 %. The patients were divided in the atherosclerotic plaque vs. non-plaque groups. There were significant differences in age, sex, blood pressure, blood glucose, serum creatinine, and history of gout and hyperuricemia between the plaque and non-plaque groups (all P < 0.05). Among the patients with coronary plaques, there were 348 patients (78.9 %) with simple atherosclerotic plaque (AP), 8 (1.8 %) with simple urate depositions (UD), and 85 (19.3 %) with urate depositions and atherosclerotic plaques (UDAP). The multivariable analysis showed that urate deposition was independently associated with plaques after adjustment for age, sex, blood pressure, blood glucose, serum creatinine, history of gout, and history of hyperuricemia (OR = 13.69, 95%CI: 7.53–22.95, P = 0.035). UPAP patients had significantly higher coronary calcium scores than AP patients [210.1 (625.2) AU vs 58.2 (182.5) AU, P < 0.001] Urate deposition (16.7 mm3) positively correlated with plaque calcification (73.8 mm³) in UPAP patients (r = 0.325, P < 0.001). ConclusionPatients with gout or a history of hyperuricemia were more likely to exhibit UDAP. Urate deposition was independently associated with plaques.

Diagnostic Performance of Cardiac CT and Transthoracic Echocardiography for Detection of Surgically Confirmed Bicuspid Aortic Valve: Effect of Calcium Extent and Valve Subtypes.

This study aimed to compare the diagnostic performance of cardiac CT and transthoracic echocardiogram (TTE) depending on the degree of valvular calcification and bicuspid aortic valve (BAV) subtype. This retrospective study included 266 consecutive patients (106 with BAV and 160 with tricuspid aortic valve) who underwent cardiac CT and TTE before aortic valve replacement. Cardiac CT was used to evaluate the morphology of the aortic valve, and a calcium scoring scan was used to quantify valve calcium. The aortic valves were classified into fused and two-sinus types. The diagnostic accuracy of cardiac CT and TTE was calculated using a reference standard for intraoperative inspection. CT demonstrated significantly higher sensitivity, negative predictive value, and accuracy than TTE in detecting BAV (p < 0.001, p < 0.001, and p = 0.003, respectively). The TTE sensitivity tended to decrease as valvular calcification increased. The error rate of TTE for CT was 10.9% for the two-sinus type of BAV and 28.3% for the fused type (p = 0.044). Cardiac CT had a higher diagnostic performance in detecting BAV than TTE and may help diagnose BAV, particularly in patients with severe valvular calcification.

Association between plaque localization in proximal coronary segments and MACE outcomes in patients with mild CAC: Results from the EISNER study

ObjectiveCoronary artery calcium score (CAC) is a validated tool to predict and reclassify cardiovascular risk. Additional metrics such as regional distribution and extent of CAC over Agatston CAC score may allow further risk stratification. In this study, we evaluate the prognostic significance of proximal CAC involvement in asymptomatic population from the prospective EISNER (Early-Identification of Subclinical Atherosclerosis by Noninvasive Imaging Research) registry, focusing on patients with mild CAC (score 1-99). MethodsThis study included a total of 2,047 adult asymptomatic subject who underwent baseline CAC scan and 14-year follow-up for MACE, defined as myocardial infarction, late revascularization, or cardiac death. Proximal involvement was defined as presence of CAC in the LM, proximal LAD, LCX or RCA. CAC was categorized as 0, 1-99, and ≥100. Results1,090 (53.2%) subjects had no CAC, 576 (28.1%) had CAC 1-99, and 381 (18.7%) had CAC ≥100. Proximal involvement was seen in 67.2% of subjects with CAC 1-99 and 97.3% of subjects with CAC ≥100. In the CAC 1-99 category, the presence of proximal CAC was associated with increased MACE risk after adjustment for CAC score, CAC extent and conventional risk factors compared to those without proximal CAC (HR: 2.84 95% CI: 1.29-6.25, p=0.009). ConclusionIn asymptomatic subjects with CAC scores of 1-99, the presence and extent of proximal CAC plaques provides strong independent prognostic information in predicting MACE

Coronary artery calcium score scan at 100 kVp with tin filtration (Sn100 kVp) prior to coronary computed tomography angiography for overall radiation dose reduction: a prospective cohort study.

BackgroundReducing radiation dose is a global concern in coronary computed tomography angiography (CCTA). We aimed to investigate whether a coronary artery calcium score (CACS) scan would lead to an overall reduction of radiation dose in CCTA examination and determine its necessity in routine CCTA imaging.MethodsA total of 297 patients with suspected coronary heart disease were consecutively enrolled in this prospective cohort study between March 1, 2021, and September 1, 2021. All patients were scanned using a prospective electrocardiogram-triggered sequence acquisition mode on a dual-source computed tomography (CT) scanner. The first 1–150 patients (group A, n=150) were scanned with CACS using tin filtration with low voltage (Sn100 kVp) to guide the CCTA scanning range, whereas the subsequent 151–297 patients (group B, n=147) were scanned using a scout view for the CCTA range. Participant characteristics, number of scans, scan length, actual heart length, CT dose index (CTDIvol), dose-length product (DLP), effective dose (ED), and qualitative analysis were statistically analyzed between the groups.ResultsThere was no significant difference in sex, age, height, weight, body mass index (BMI), or heart rate between the 2 groups. The number of scans and scan length (149 of 3 scans at 10.35 cm, 1 of 4 scans at 13.80 cm; P<0.001), CTDIvol of CCTA (16.13 mGy; P<0.04), DLP of CCTA (166.90 mGy*cm; P<0.001), ED of CCTA (4.34 mSv; P<0.001), and overall ED (4.57 mSv; P<0.001) of group A showed significant differences compared with group B (36 of 3 scans at 10.35 cm, 109 of 4 scans at 13.80 cm, 2 of 5 scans at 17.25 cm; CTDIvol of CCTA at 18.30 mGy; DLP of CCTA at 235.60 mGy*cm; ED of CCTA at 6.13 mSv; overall ED at 6.13 mSv); meanwhile, actual heart length, qualitative analysis, and diagnostic CT reports were similar between the groups.ConclusionsThe CACS scan with Sn100 kVp prior to CCTA imaging on dual-source CT could reduce overall radiation dose.

Impact of an ultra-low dose unenhanced planning scan on CT coronary angiography scan length and effective radiation dose.

ObjectiveImaged scan length (z-axis coverage) is a simple parameter that can reduce CT dose without compromising image quality. In CT coronary angiography (CTCA), z-axis coverage may be planned using non-contrast calcium score scan (CaCS) to identify the relevant coronary anatomy. However, standardised Agatston CaCS is acquired at 120 kV which adds a relatively high contribution to total study dose and CaCS is no longer routinely recommended in UK guidelines. We evaluate an ultra-low dose unenhanced planning scan on CTCA scan length and effective radiation dose.Methods:An ultra-low dose tin filter (Sn-filter) planning scan (100 kVp, maximum iterative reconstruction) was performed and used to plan the z-axis coverage on 48 consecutive CTCAs (62% men, 62 ± 13 years) compared with 47 CTCA planned using a localiser alone (46% men, 59 ± 12 years) between May and June 2019. Excess scanning beyond the ideal scan length was calculated for both groups. Estimations of radiation dose were also compared between the two groups.Results:Addition of an ultra-low dose unenhanced planning scan to CTCA protocol was associated with reduction in overscanning with no impact on image quality. There was no significant difference in total study effective dose with the addition of the planning scan, which had an average dose–length product of 3 mGy.cm. (total study dose: Protocol A 2.1 mSv vs Protocol B 2.2 mSv, p = 0.92).Conclusion:An ultra-low dose unenhanced planning scan facilitates optimal scan length for the diagnostic CTCA, reducing overscanning and preventing incomplete cardiac imaging with no significant dose penalty or impact on image quality.Advances in knowledge:An ultra-low dose CTCA planning is feasible and effective at optimising scan length.

Abstract 12220: Deep Learning Segmentation and Quantification of Epicardial Adipose Tissue in CT Calcium Score Images

Introduction: Studies have linked the epicardial adipose tissue (EAT) volume with the risk of adverse cardiovascular (CV) events, suggesting a role for clinical decision making. Manual quantification of EAT is time-consuming, requires specialized training, and is prone to human error, thus limiting its routine use in clinical practice. Hypothesis: Deep-learning approach can facilitate EAT quantification on archival coronary artery calcium scoring (CAC) scans. Methods: We developed a deep learning semantic segmentation method using the DeepLab-v3 plus network and applied it to gated, non-contrast cardiac CT calcium score scans. Analysts manually identified the enclosing pericardial sac using interactive visualization software. Our algorithm was trained to segment the image region enclosed by the pericardial sac. To keep the sac-increasing curvature, we segmented the heart into two halves. The lower half was analyzed from bottom-to-middle, while the slices in the upper half were analyzed from top-to-middle. Each 2D slice was associated with two consecutive slices, giving a three-slice image slab. A window/level of 350/40 Hounsfield unit (HU) was applied to axial slices providing a uniform HU-attention-window. A median filter with kernel size 3mm was applied to reduce noise. After deep learning semantic segmentation of the enclosing region, we determined EAT using the standard CT fat window [-190, -30] HU. Results: Using 89 CT scans (50 training/39 testing), our algorithm showed excellent results compared to ground-truth manual labeling. The total average Dice score was (88.52%±3.35) with a high correlation against manually derived EAT (R=98.52%, p-value&lt;0.001). The average Dice score per slice was 91.80% (with R=96.62%, p-value&lt;0.001). The average percent EAT volume error was only 5.74%±5.04. Conclusions: Our developed end-to-end deep learning segmentation approach, using HU-attention-window and slab-of-slices gives accurate EAT volume segmentation. Our results provide an important avenue for automated analysis of EAT and its relationship with CV events in large data sets.

Prediction of obstructive coronary artery disease after Rb-82 PET myocardial perfusion imaging and coronary artery calcium scoring using machine learning

Abstract Funding Acknowledgements Type of funding sources: None. Background Accurate risk stratification in patients with suspected stable coronary artery disease (CAD) is essential for choosing an appropriate treatment strategy but remains challenging in clinical practice. Purpose Our aim was to develop and validate a risk model to predict the presence of obstructive CAD after Rubidium-82 PET and a coronary artery calcium score (CACS) scan using a machine learning (ML) algorithm. Methods We retrospectively included 1007 patients without prior cardiovascular history and a low-intermediate pre-test likelihood, referred for rest and regadenoson-induced stress Rubidium-82 PET combined with a CACS scan. Multiple features were included in the ML model; PET derived features such as summed difference score and flow values, CACS, cardiovascular risk factors (cigarette smoking, hypertension, hypercholesterolemia, diabetes, positive family history of CAD), medication; age; gender; body mass index; creatinine serum values; and visual PET interpretation. An XGBoost ML algorithm was developed using a subset of 805 patients to predict obstructive CAD by using 5-fold cross validation in combination with a grid search. Obstructive CAD during follow-up was defined as a significant stenosis during invasive coronary angiography, a percutaneous coronary intervention or a coronary artery bypass graft procedure. The ML algorithm was validated with unseen data of the remaining 202 patients. Results Application of the XGBoost algorithm resulted in an area under the curve (AUC) of 0.93 using the training data (n = 805) and an AUC of 0.89 using the unseen data (n = 202) in predicting obstructive CAD. The strongest predictors were the CAC-scores and quantitative PET derived features. The classical risk factors and medication hardly provided an added value in the prediction of obstructive CAD. Conclusion The developed ML algorithm is able to provide individualized risk stratification by predicting the probability of obstructive CAD. Although validation with a larger dataset could result in a more well defined performance range, this model already shows potential to be implemented in the diagnostic workflow.

Implementing Coronary CT for Routine Annual Surveillance of Cardiac Allograft Vasculopathy in Heart Transplant Patients

<h3>Purpose</h3> Cardiac allograft vasculopathy (CAV) is an accelerated form of coronary artery disease that affects heart transplant (HT) patients. Routine surveillance for CAV is warranted. We evaluated the feasibility, utility and safety of cardiac CT to screen for CAV in HT patients. <h3>Methods</h3> From Feb 2018 to Jul 2019 all HT patients >four years post-HT were converted from using stress myocardial perfusion imaging for the annual CAV surveillance to cardiac CT (calcium score scan and CT angiography (CTA)). All first scans were included. Scans were scored for image quality (non-diagnostic, moderate, good, excellent), Agatston calcium score and coronary stenosis (0%, <50% or ≥50%). CAV score (similar to ISHLT guidelines) based on CT findings was compared to the most recent CAV score (based on invasive angiography and perfusion imaging). Major adverse cardiovascular events (MACE) were scored one-year post-CT. <h3>Results</h3> In total, 141 CT scans were included. CTA was performed in 140 out of 141 patients who were planned for cardiac CT (55 (43-64) years, 66% men, and 11 (8-16) years post-HT). One patient only had a calcium score due to no IV access. Mean heart rate during CTA was 75±11 beats per minute with beta-blockers given in 90 patients. Image quality was good/excellent in 124 (89%) scans. Median radiation dose was 2.1 (1.6-2.9) mSv. Median Agatston calcium score was 4 (0-73), 56 (40%) patients had no detectable calcium. CTA showed new obstructive coronary disease (≥50% stenosis) in 25 (18%) patients (Figure 1). CTA reclassified CAV score in 49 (35%) patients (p<0.001). There were 78 CAV0, 30 CAV1, 15 CAV2 and 17 CAV3 patients. MACE occurred in 8 (6%) patients in the year post-CCTA (2 deaths (rejection + cancer), 5 CVAs, 2 myocardial infarctions (type 4 MI + NSTEMI in known CAV)). <h3>Conclusion</h3> Cardiac CT can be performed successfully in HT patients with good/excellent image quality and low radiation dose. CTA successfully detects significant CAV which leads to substantial reclassification of CAV grades.

Longitudinal Progression of Subclinical Coronary Atherosclerosis in Swiss HIV-Positive Compared With HIV-Negative Persons Undergoing Coronary Calcium Score Scan and CT Angiography.

BackgroundPeople with HIV (HIV+) may have increased cardiovascular event rates compared with HIV-negative (HIV-) persons. Cross-sectional data from the United States and Switzerland, based on coronary artery calcium scan (CAC) and coronary computed tomography angiography (CCTA), suggest, respectively, increased and similar prevalence of subclinical atherosclerosis in HIV+ vs HIV- persons.MethodsWe repeated CAC/CCTA in 340 HIV+ and 90 HIV- study participants >2 years after baseline CAC/CCTA. We assessed the association of HIV infection, Framingham risk score (FRS), and HIV-related factors with the progression of subclinical atherosclerosis.ResultsHIV+ were younger than HIV- participants (median age, 52 vs 56 years; P < .01) but had similar median 10-year FRS (8.9% vs 9.0%; P = .82); 94% had suppressed HIV viral load. In univariable and multivariable analyses, FRS was associated with the incidence rate ratio (IRR) of new subclinical atherosclerosis at the follow-up CAC/CCTA, but HIV infection was not: any plaque (adjusted IRR for HIV+ vs HIV- participants, 1.21; 95% CI, 0.62–2.35), calcified plaque (adjusted IRR for HIV+ vs HIV- participants, 1.06; 95% CI, 0.56–2), noncalcified/mixed plaque (adjusted IRR for HIV+ vs HIV- participants, 1.24; 95% CI, 0.69–2.21), and high-risk plaque (adjusted IRR for HIV+ vs HIV- participants, 1.46; 95% CI, 0.66–3.20). Progression of CAC score between baseline and follow-up CAC/CCTA was similar in HIV+ (median annualized change [interquartile range {IQR}], 0.41 [0–10.19]) and HIV- participants (median annualized change [IQR], 2.38 [0–16.29]; P = .11), as was progression of coronary segment severity score (HIV+: median annualized change [IQR], 0 [0–0.47]; HIV-: median annualized change [IQR], 0 [0–0.52]; P = .10) and coronary segment involvement score (HIV+: median annualized change [IQR], 0 [0–0.45]; HIV-: median annualized change [IQR], 0 [0–0.41]; P = .25).ConclusionsIn this longitudinal CAC/CCTA study from Switzerland, Framingham risk score was associated with progression of subclinical atherosclerosis, but HIV infection was not.

Influence of contrast material density and kV setting on detectability of calcified plaques on coronary CT angiography

PurposeTo analyze the impact of tube potential and iodine concentration on the visibility of calcified plaques in coronary computed tomography angiography (cCTA). Methods & Materials164 consecutive patients (65.9 % men and a mean age of 57.1 ± 11.3 years) with suspected coronary artery disease underwent calcium scoring (CaSc) scan followed by cCTA with topogram-based automated tube voltage selection (70 kV, 80 kV, 90 kV, 100 kV or 120 kV). In 127 Patients (HC), we injected 50 mL of contrast material (CM) with a concentration of 400 mg iodine per ml and in 37 patients (LC) 50 mL iodine concentration of 280 mg/mL. Sensitivity of cCTA for detecting calcified plaques was calculated with CaSc serving as gold standard. Density of CM enhanced coronary vessels and calcified plaques were quantified by region-of-interest (ROI) measurements in unenhanced and cCTA image series. ResultsOverall sensitivity of cCTA to detect calcified plaques was significantly higher using LC compared to HC (79 % vs. 73 %; p = 0.0035). The impact of LC was impressive at 70 kV with an improved sensitivity of 70 % vs. 57.1 % in HC (p = 0.0082). Furthermore, density values of HC enhanced coronary vessels exceeded those of calcified plaques, especially at low kV levels. In LC, except for the 70 kV setting, higher density values were shown for calculi than enhanced vessels. ConclusionLow kV cCTA in routine using highly concentrated CM leads to reduced calcified plaque perceptibility and hence potentially underestimation of stenosis. Thus, low kV cCTA using CM with lower iodine concentration is necessary. In addition, a dose reduction up to 77.7 % can also be benefited.

The Mechanism of Coronary Artery Calcification in Centrally Obese Non-Diabetic Men: Study on The Interaction of Leptin, Free Leptin Index, Adiponectin, hs-C Reactive Protein, Bone Morphogenetic Protein-2 and Matrix Gla Protein

Background: The calcium in the artery was thought to be the result of the imbalance or dysregulation of the promoter and inhibitor cytokines influenced by various subclinical and clinical conditions. This study aimed to investigate the interaction between central obesity, as an early subclinical condition, also known as a chronic low grade inflammation condition and coronary artery calcium (CAC) in non-diabetic population including the underlying pathomechanisms of a CAC in the early stage of atherosclerosis.Materials and Methods: This was a cross-sectional pathway analysis study enrolling 60 central obesity non-diabetic men that underwent coronary calcium score scan, anthropometrics and biomarker assays.Results: There was a positive correlation between increasing free leptin index/adiponectin (FLI/A) ratio and CAC (r=0.297; p&lt;0.05). There was a positive correlation between increasing FLI/A ratio and plasma high sensitive C-reactive protein (hs-CRP) (r=0.318; p&lt;0.05). Plasma hs-CRP and bone morphogenetic protein-2 (BMP-2)-matrix gla protein (MGP) dysregulation were positively correlated (r=0.221; p&lt;0.05) after adjusted to risk factors including insulin resistance, hypertension, age, and dyslipidemia.Conclusion: The study found that one of the pathways involved in CAC in the centrally obese non-diabetic male is might be due to an increase of free leptin and decrease of adiponectin. The free leptin and adiponection ratio also increased hs-CRP, which partially correlated to the dysregulation of BMP-2 and MGP.Keywords: coronary artery calcification, central obesity, adipokines, bone regulator protein, pathomechanism

Can the Coronary Artery Calcium Score Scan Reduce the Radiation Dose in Coronary Computed Tomography Angiography?

Radiation exposure from coronary computed tomography angiography (CCTA) remains a cause for concern. The objective of this study was to investigate whether using the coronary artery calcium score scan (CACS) would reduce the radiation dose for CCTA scanning and the overall radiation exposure (ORE). In total, 256 patients were examined with a third-generation dual-source CT (n = 200) or 256-row CT (n = 56), among whom 105 (Group A) and 28 patients (Group B), respectively, underwent CCTA with CACS for field of view planning. The remaining patients, with the scout view for field of view planning, constituted Group A1 and B1. The scanning parameter settings were standardized between groups. Shorter scan lengths were observed in Group A (9.98 ± 0.79 cm) compared to Group A1 (13.64 ± 1.79 cm; p < 0.001), which also resulted in a lower dose-length product (DLP) in Group A (115.04 ± 64.13) relative to Group A1 (138.67 ± 68.87; p < 0.05). Similarly, shorter scan lengths were found in Group B (14.92 ± 1.17 cm) compared to Group B1 (15.79 ± 0.63 cm; p = 0.001); this resulted in a lower DLP (322.07 ± 45.39) compared to Group B1 (354.34 ± 65.27; p = 0.036). The CACS resulted in an increase in ORE in both groups. CACS may have a critical role in the reduction of radiation dose in CCTA scanning, but the potential effectiveness of CACS in reducing ORE is weak.

Non-contrast cardiac CT-based quantitative evaluation of epicardial and intra-thoracic fat in healthy, recently menopausal women: Reproducibility data from the Kronos Early Estrogen Prevention Study

BackgroundCardiac fat is emerging as an important parameter for cardiovascular risk stratification. Accurate and reproducible volumetric measurements can facilitate in the serial assessment of cardiac fat by computed tomography (CT). We assessed the intra- and inter-observer variability of cardiac fat volumetric measurements using a semi-automated CT software. MethodsWe used non-contrast coronary calcium CT scans to quantify epicardial and intra-thoracic fat volumes. Two expert readers analyzed baseline and follow up CT scans of 45 subjects by using a semi-automated CT software (QFAT 2.0, Cedars Sinai-Medical Center). Correlation and Bland-Altman analysis was performed for both intra- and inter-observer comparisons for each cardiac fat type. ResultsThe intra-observer correlation coefficients ranged between 0.86 to 0.99 and 0.87 to 0.99 for epicardial (median fat per reader (cm3) 20.9 to 25.7) and intra-thoracic (median fat per reader (cm3) 27.1 to 31.6) fat volumes respectively, with no significant differences between individual data points (all p > 0.38). The inter-observer correlation coefficient was 0.99 (p < 0.0001 for correlation) for both epicardial and intra-thoracic fat. By Bland-Altman analysis for epicardial fat measurements, mean difference of intra-observer was 0.90 cm3 with 95% confidence intervals (0.22,1.7) and −1.8 cm3 for inter-observer, with 95% CI (−2.9, −0.69). Bland-Altman plots for intra-thoracic fat measurements were similarly impressive for both inter- and intra-observer reads. ConclusionsOur data showed that measuring epicardial and intra-thoracic fat volumes by CT using a semi-automated software has excellent intra-observer and inter-observer reliability. Cardiac fat volumes can be obtained easily and reproducibly from routine calcium scoring scans and may help in assessing cardiovascular risk. Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT00154180; Keywords: Epicardial fat volume; intra-thoracic fat volume; computed tomography; intra-observer; inter-observer.

Benefits of adding coronary calcium score scan to stress myocardial perfusion positron emission tomography imaging.

There have been little and conflicting data regarding the relationship between coronary artery calcification score (CACS) and myocardial ischemia on positron emission tomography myocardial perfusion imaging (PET MPI). The aims of this study were to investigate the relationship between myocardial ischemia on PET MPI and CACS, the frequency and severity of CACS in patients with normal PET MPI, and to determine the optimal CACS cutoff point for abnormal PET. This retrospective study included 363 patients who underwent same-setting stress PET perfusion imaging and CACS scan because of clinically suspected coronary artery disease (CAD). Fifty-five (55%) of the 363 patients had abnormal PET perfusion. There was an association between sex, diabetes mellitus (DM), smoking, and CACS and PET perfusion abnormities with P = 0.003, 0.05, 0.005, and 0.001, respectively. However, there was no association between PET perfusion abnormalities with age, body mass index, hypertension, and hypercholesterolemia. There was association between CACS and age, sex, and DM with P = 0.000, 0.014, and 0.052, respectively, and stepwise increase in the frequency of myocardial ischemia and CACS groups. Receiver-operating characteristic analysis showed that a CACS ≥304 is the optimal cutoff for predicting perfusion abnormalities with sensitivity of 64% and specificity of 69%. In conclusion, the frequency of CAC in patients with normal PET MPI is 49%, it is highly recommended to combine CACS with PET MPI in patients without a history of CAD. PET MPI identifies myocardial ischemia and defines the need for coronary revascularization, but CAC reflects the anatomic burden of coronary atherosclerosis. Combining CACS to PET MPI allows better risk stratification and identifies high-risk patients with PET, and it may change future follow-up recommendations. CACS scan is readily available and easily acquired with modern PET-computed tomography (CT) and single-photon emission CT (SPECT)-CT with modest radiation exposure.

Left atrial volume quantification using coronary calcium score scan: Feasibility, reliability and reproducibility analysis of a standardized approach

BackgroundLeft atrial volume (LAV) is an independent prognosticator of cardiovascular events. We investigated whether LAV could be accurately and reliably measured using coronary calcium score (CAC) scan. MethodsWe retrospectively selected consecutive patients that underwent coronary CT angiography (CCTA) and CAC scans. A standardized approach to calculate LAV on images was implemented. The measurements of the LAV on CAC scans and CCTA were performed one to three weeks apart in a random fashion by two readers blinded to the results of each other. The LAV measurements from CAC scan were compared to those from CCTA using correlation analysis. Inter-observer and intra-observer agreement of LAV measurement using CAC scan was evaluated. ResultsFinal analysis included one hundred subjects, mean age 52 ± 12 years, 48% male. There was a trend of a marginally larger, albeit not clinically significant, mean LAV calculated using CAC scan compared to that using CCTA: 74.3 vs. 71.0 mL: p < 0.001; for reader 1, and 71.7 vs. 71.2 mL p = 0.06 for reader 2, respectively. LAV using CAC scan and CCTA were highly correlated (R = 0.954, p < 0.001 for reader1 and R = 0.945, p < 0.001 for reader 2). There was high reproducibility within each reader with ICC of 0.951 and 0.989 for readers 1 and 2, respectively (p < 0.001). Finally, there was high inter-observer agreement as indicated by R of 0.97 and ICC of 0.96 (p < 0.001 for both). ConclusionsQuantification of LAV from CAC scan using the proposed standardized approach is feasible, highly reliable and reproducible as compared to CCTA.

Diagnostic Phase of Calcium Scoring Scan Applied as the Center of Acquisition Window of Coronary Computed Tomography Angiography Improves Image Quality in Minimal Acquisition Window Scan (Target CTA Mode) Using the Second Generation 320-Row CT.

Objective. To compare the image quality of coronary computed tomography angiography (CCTA) acquired under two conditions: 75% fixed as the acquisition window center (Group 75%) and the diagnostic phase for calcium scoring scan as the center (CS; Group CS). Methods. 320-row cardiac CT with a minimal acquisition window (scanned using “Target CTA” mode) was performed on 81 patients. In Group 75% (n = 40), CS was obtained and reconstructed at 75% and the center of the CCTA acquisition window was set at 75%. In Group CS (n = 41), CS was obtained at 75% and the diagnostic phase showing minimal artifacts was applied as the center of the CCTA acquisition window. Image quality was evaluated using a four-point scale (4-excellent) and the mean scores were compared between groups. Results. The CCTA scan diagnostic phase occurred significantly earlier in CS (75.7 ± 3.2% vs. 73.6 ± 4.5% for Groups 75% and CS, resp., p = 0.013). The mean Group CS image quality score (3.58 ± 0.63) was also higher than that for Group 75% (3.19 ± 0.66, p < 0.0001). Conclusions. The image quality of CCTA in Target CTA mode was significantly better when the center of acquisition window is adjusted using CS.

The use of ct calcium scoring, heart age, and myocardial perfusion scan in risk stratification of patients with familial hypercholesterolaemia

The use of ct calcium scoring, heart age, and myocardial perfusion scan in risk stratification of patients with familial hypercholesterolaemia

Association of aortic root calcification severity with the extent of coronary artery calcification assessed by calcium-scoring dual-source computed tomography

PurposeTo investigate the association between aortic root calcification (ARC) and coronary artery calcification (CAC) assessed by coronary artery calcium-scoring dual-source computed tomography (DSCT). Materials and methodsWe retrospectively analyzed 143 consecutive patients who underwent coronary artery calcium-scoring during coronary DSCT angiography. 57 patients had findings of ARC on calcium-scoring scans. ARC volume (ARCV) and Agatston coronary artery calcium score (CACS) were calculated. Chi-square test was used to assess differences of categorical variables between patients with and without ARC. Statistical significances between both groups were assessed with the independent-Sample t test. ResultsCompared with patients without ARC (n=86), patients with ARC (n=57) showed a significantly higher presence of CAC (87.7% vs. 24.4%; P<0.001), and a higher mean CACS (700.6±941.2 vs. 256.4±724.3; P=0.009) in patients with CAC. Patients with a calculated ARCV >40mm3 (n=32) showed significantly higher rates of severe CAC (56.3% vs. 24.0%; P=0.014) compared with patients with an ARCV<40mm3 (n=25). Compared with patients without CAC (n=42), patients with CAC (n=101) showed a significantly higher presence of ARC (83.3% vs. 50.5%; P<0.001) and a higher mean ARCV (95.4±116.2mm3 vs. 29.7±33.0 mm3; P=0.003). Severe CAC (n=24) correlated with an increased mean ARCV (122.3±148.8mm3) compared to patients with minimal to moderate CAC (n=33, mean ARCV: 61.9±64.8mm3; P<0.05). ConclusionsThe extent of ARC is directly associated with the presence and degree of CAC on calcium-scoring scans during coronary DSCT angiography.

The Prevalence and Extent of Coronary Atherosclerosis among Patients with a Zero Calcium Score and the Influence of Patient Characteristics

Coronary artery calcium (CAC) is a specific indicator of and an independent risk factor for atherosclerosis; however, calcium scoring may miss noncalcified plaques, which may have clinical importance. The aim of this study was both to identify the presence and extent of coronary plaques during computed tomography coronary angiography (CTCA) in patients with a zero CAC score and to evaluate the effect of risk factors and symptom status on the presence of noncalcified plaques. In this retrospective study, we analyzed the cases of 842 consecutive patients between October 2006 and November 2011. Of these patients, we included 357 with a zero calcium score in the study. Information regarding patient age, sex, coronary risk factors, and symptom status were recorded. Coronary calcium-scoring scans were followed by CTCA. The calcium scores were calculated, and the presence of noncalcified plaques and significant stenoses (>50% of vessel diameter) was evaluated. Of the 357 patients with a zero calcium score, 37 (10.36%) had atherosclerotic plaques; 9 patients (2.52%) had significant coronary stenosis. Among coronary risk factors, only diabetes mellitus was significantly correlated with any risk factors (presence of atherosclerosis and obstructive coronary artery disease; P = .030 and .013, respectively). Although CAC scoring is a safe and a reliable test to exclude obstructive coronary artery disease, the absence of CAC does not definitively exclude the presence of atherosclerosis. CTCA is a more appropriate method for determining the atheroma burden.

Computed tomography calcium score scan for attenuation correction of N-13 ammonia cardiac positron emission tomography: effect of respiratory phase and registration method

The use of coronary calcium scoring (CaScCT) for attenuation correction (AC) of (13)N-ammonia PET/CT studies (NH3) is still being debated. We compare standard ACCT to CaScCT using various respiratory phases and co-registration methods for AC. Forty-one patients underwent a stress/rest NH3. Standard ACCT scans and CaScCT acquired during inspiration (CaScCTinsp, 26 patients) or expiration (CaScCTexp, 15 patients) were used to correct PET data for photon attenuation. Resulting images were compared using Pearson's correlation and Bland-Altman (BA) limits of agreement (LA) on segmental relative and absolute coronary blood flow (CBF) using both manual and automatic co-registration methods (rigid-body and deformable). For relative perfusion, CaScCTexp correlates better than CaScCTinsp with ACCT when using manual co-registration (r = 0.870; P < 0.001 and r = 0.732; P < 0.001, respectively). Automatic co-registration provides the best correlation between CaScCTexp and ACCT for relative perfusion (r = 0.956; P < 0.001). Both CaScCTinsp and CaScCTexp yielded excellent correlations with ACCT for CBF when using manual co-registration (r = 0.918; P < 0.001; BA mean bias 0.05 ml/min/g; LA: -0.42 to +0.3 ml/min/g and r = 0.97; P < 0.001; BA mean bias 0.1 ml/min/g; LA: -0.65 to +0.5 ml/min/g, respectively). The use of CaScCTexp and deformable co-registration is best suited for AC to quantify relative perfusion and CBF enabling substantial radiation dose reduction.